2. The first ceremony used for devoting a person to the service of god and the church; the first degree of the clericate, given by a bishop, abbot, or cardinal priest, consisting in cutting off the hair from a circular space at the back of the head, with prayers and benedictions; hence, entrance or admission into minor orders. The shaven corona, or crown, which priests wear as a mark of their order and of their rank.
Origin: F, fr. L. Tonsura a shearing, clipping, from tondere, tonsum, to shear, shave; cf. Gr. To gnaw; perhaps akin to Gr. To cut, and E. Tome.